如何使用 "ago" 造句

1. But that was 20 years ago .
但是这是20年前。
2. That was a long time ago .
那是很久以前的事情了。
3. That would have been unthinkable 20 years ago .
这样的改变20年之前是不可思议的。
4. The nordic crises were not so long ago , yet they seem a world away .
nordic危机距今并不遥远,但看来像另一个世界的事。
5. Mr arafat died eight years ago .
阿拉法特逝于八年前。